[PATCH v3 13/14] media: platform: pxa_camera: change stop_streaming semantics

Robert Jarzmik
2016-08-08T19:39:00Z

Instead of the legacy behavior where it was required to wait for all
video buffers to be finished by the hardware, use a cancel like strategy
: as soon as the stop_streaming() call is done, abort all DMA transfers,
report the already buffers as failed and return.

This makes stop_streaming() more a "cancel capture" than a "wait for end
of capture" semantic.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
---
drivers/media/platform/soc_camera/pxa_camera.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c
index 20340489e07e..a161b64d420d 100644
--- a/drivers/media/platform/soc_camera/pxa_camera.c
+++ b/drivers/media/platform/soc_camera/pxa_camera.c
@@ -526,7 +526,8 @@ static void pxa_camera_stop_capture(struct pxa_camera_dev *pcdev)
}

static void pxa_camera_wakeup(struct pxa_camera_dev *pcdev,
- struct pxa_buffer *buf)
+ struct pxa_buffer *buf,
+ enum vb2_buffer_state state)
{
struct vb2_buffer *vb = &buf->vbuf.vb2_buf;
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
@@ -648,7 +649,7 @@ static void pxa_camera_dma_irq(struct pxa_camera_dev *pcdev,
}
buf->active_dma &= ~act_dma;
if (!buf->active_dma) {
- pxa_camera_wakeup(pcdev, buf);
+ pxa_camera_wakeup(pcdev, buf, VB2_BUF_STATE_DONE);
pxa_camera_check_link_miss(pcdev, last_buf->cookie[chan],
last_issued);
}
@@ -1090,7 +1091,15 @@ static int pxac_vb2_start_streaming(struct vb2_queue *vq, unsigned int count)

static void pxac_vb2_stop_streaming(struct vb2_queue *vq)
{
- vb2_wait_for_all_buffers(vq);
+ struct pxa_camera_dev *pcdev = vb2_get_drv_priv(vq);
+ struct pxa_buffer *buf, *tmp;
+
+ dev_dbg(pcdev_to_dev(pcdev), "%s active=%p\n",
+ __func__, pcdev->active);
+ pxa_camera_stop_capture(pcdev);
+
+ list_for_each_entry_safe(buf, tmp, &pcdev->capture, queue)
+ pxa_camera_wakeup(pcdev, buf, VB2_BUF_STATE_ERROR);
}

static struct vb2_ops pxac_vb2_ops = {
--
2.1.4